The route of the second phase of the high speed railway line – HS2 – is being announced today.
Details of the first planned section between London and Birmingham have already been published.
Now the Government will reveal the exact locations of the so-called "Y" sections.
This is where HS2 will split, east and north of Birmingham, into two major routes: one, through Staffordshire, to Manchester; the other, via the East Midlands, to Leeds.
The Government and supporters of HS2 – like some councils and many business leaders – say the railway is vital for the economy of Britain.
And, they argue, it is needed to relieve growing congestion on existing railways between the capital, the Midlands, and the North.
Another argument in its favour is that HS2 will improve what many people see as a North-South divide; an economy and transport system which appears weighted in favour of London and the South-East.
And it is said that Britain – the pioneer of railways – now lags well behind the rest of Europe and developing countries like China who have embraced high speed rail links which have brought economic benefits.
But HS2 has a great many opponents who also include some local councils and industrialists.
Today's announcements are certain to spark many new protests, and some are due to take place this morning.
Those who are fighting the railway say it's a white elephant, a waste of billions of pounds, especially at a time when the Government's current economic policy is one of austerity and financial cutbacks.
Objectors say it will destroy many thousands of acres of picturesque countryside, including traditional English villages and numerous ancient woodlands which will be lost forever.
Many homes and businesses will have to be demolished, and people who remain will face noise from trains as well as years of disruption during building work.
Whilst some environmentalists prefer railway transport to roads and aircraft routes, there is concern among them that HS2 will not be as "green" as its supporters make out.
Millions of tons of concrete will have to be used in its construction and high speed trains need greater amounts of electricity - much of which, at the moment, is provided by fossil fuels.
The anti-HS2 campaigners argue that, far from relieving congestion, it will lead to a poorer service on current railway routes like the West Coast, East Coast, and Midland main lines.
And they claim it will be a railway for the rich, subsidised by the poor.
Far from ending the North-South divide, they believe it will create even more unfairness – with London and the South-East getting more benefits than those living and working at the other end of the tracks.
This was a plan originally conceived by Labour but carried on, albeit in a changed form, by the Coalition.
But some Tories are worried about the potential impact not just on the environment and economy, but on their constituencies, where there has already been a backlash.
The railway will serve only major cities – so many thousands of people living close to it will not be served, directly, by it.
Plans for the London to Birmingham section of the line are currently subject to a judicial review in response to objections that the consultation process was unfair and flawed.
One possibility is that consultations will have to be held again, leading to delays.Details of the "Y" routes have been widely leaked to various newspapers.
It has been reported that the lines will split at Water Orton, east of Birmingham, with the line to Leeds heading towards Nottingham and Derby and going under East Midlands Airport.
There are plans for a station at the giant Toton sidings near Nottingham, which would mean people in the centre of the city would have to travel out of town to use HS2.
Once at Toton – a journey of 17 minutes from Nottingham centre, according to Nottinghamshire County Council – the claim is that passengers will reach London in 51 minutes.